(function(window , undefined ){
    var Ygtoast = function(){ //构造函数大驼峰命名法
    };
    Ygtoast.prototype={  //prototype 属性使您有能力向对象添加属性和方法。
        create: function(str,duration) {
            let self = this;
            var toastHtml = '';
            var toastText = '<div class="yg-toast-text">'+str+'</div>';
            toastHtml = '<div class="yg-toast">'+toastText+'</div>';
            if(document.querySelector(".yg-toast"))return;    //当还没hide时禁止重复点击
            document.body.insertAdjacentHTML('beforeend', toastHtml);
            duration == null ? duration=2000 : '';  //如果toast没有加上时间，默认2000毫秒；
            self.show();
            setTimeout(function(){
                self.hide();
            }, duration);
        },
        show:function(){
            let self = this;
            document.querySelector(".yg-toast").style.display = "block";
            document.querySelector(".yg-toast").style.marginTop =  "-"+Math.round(document.querySelector(".yg-toast").offsetHeight/2)+"px";
            if(document.querySelector(".yg-toast"))return;
        },
        hide:function(){
            var self = this;
            if(document.querySelector(".yg-toast")){
                document.querySelector(".yg-toast").parentNode.removeChild(document.querySelector(".yg-toast"));
            }
        },
        toast:function(str,duration){
            var self = this;
            return self.create(str,duration);
        }
    };
    window.Ygtoast = Ygtoast;
}(window));
